LAUSR

Abstract Landslide risk arises from the combination of hazard, the exposed population and their vulnerabilities. Whereas hazard depends on natural and anthropogenic factors that render the slopes susceptible to mass movements, vulnerability is related to community conditions that render it susceptible to the damaging effects. As disaster risk management (DRM) usually tends to focus on the physical aspects of the problem, it is common to neglect the level of vulnerability among exposed populations to landslide threats, a practice which may compromise the efficiency of DRM policies. This paper presents a method to evaluate vulnerability and combine it with hazard and exposure, using data sourced from the Brazilian Institute of Geography and Statistics (IBGE) census information and hazard mapping. The method includes procedures for spatial compatibilization of the three components, definition of values for each, and the manner by which they are combined. The method was applied to the municipality of Angra dos Reis in Rio de Janeiro State, Brazil. The results indicated that vulnerability has a significant influence on risk estimation and, hence, in the spatial distribution of risk levels – 66% of risk sectors had their ratings altered after consideration of this component, corresponding to 58% of the total area mapped, in which 58% of the population lives.